1. Field of the Invention
The present invention relates generally to improvements in vehicle burnt gas exhaust systems and more particularly pertains to a new and improved exhaust pipe extension apparatus and method wherein the length of the exhaust system is extendable.
2. Description of the Related Art
In the field of exhaust pipe extension systems for motor vehicles, it has been the practice to extend or retract the exhaust pipe extension components based upon the sensing of engine revolutions per minute (“RPM”). In two-stroke engines, the passage length of the exhaust system is an important factor in engine performance. The length of an exhaust system is normally selected to correspond with the engine RPM at which maximum power is to be achieved. Variable length exhaust systems utilizing exhaust extension components which are controlled according to engine speed permit maximum engine efficiency at multiple engine RPMs, rather than at only one engine speed. Exhaust extension elements have also been utilized for tuning the acoustic performance of the exhaust system. “Whistle tips” and other components have been fashioned to connect to the end or within the exhaust pipe to produce varying auditory noises or pitches. Some tips are fixed or welded in place, while others utilize rotatable or slidable components. These systems do not address the problem solved by the present invention.
Prior art exhaust extension systems do not address the significant problem of toxic exhaust fumes from an internal combustion engine entering the passenger cabin of an automobile. Not only is the smell of exhaust fumes unpleasant, it poses severe health risks if inhaled. When exhaust gas is introduced into a closed area, such as the passenger cabin of a vehicle, the health risk to humans or animals becomes acute.
A well known toxic component of exhaust gas is carbon monoxide. When inhaled, carbon monoxide replaces oxygen in the lungs and causes serious injury or death to humans. Breathing even low levels of carbon monoxide leads to headaches or problems with vision and coordination. These physical impairments become dangerous while driving an automobile. Carbon monoxides, nitrogen oxides and hydrocarbons are also present in the exhaust fumes. These are known to cause eye, nose, throat and respiratory problems. Despite improvements in engine efficiency and compliance with stricter emissions standards focused on reducing such pollutants, exhaust gas from internal combustion engines continue to threaten the health of individuals.
When a vehicle sits at idle with its engine running, the surrounding environment and wind conditions play a significant role in dispersing the exhaust gas. When the vehicle is moving forward, a vacuum effect at the rear-end of the vehicle caused by the aerodynamics of the automobile pulls the exhaust gas underneath the vehicle. The exhaust gas circulates underneath the automobile where it can potentially enter the passenger cabin.
Current attempts at reducing the intake of exhaust fumes into the passenger compartment have been the use of plugs or seals to close manufacturing or other holes in the vehicle leading into the passenger compartment. Foam products encapsulating certain underbody components have been used to help limit the entrance of exhaust gas into the interior of the vehicle cabin. This effort has been directed solely at limiting the number of passageways that lead into the passenger compartment. Other attempts have been directed to arranging parts on the automobile in order to alter the airflow of the moving vehicle in a way that disperses the exhaust gas. The exhaust pipe on the automobile, for example, can be reconfigured to discharge the exhaust gas out the side of the vehicle rather than out the rear of the vehicle.
These attempted solutions, however, have significant drawbacks. Sealing of apertures adds increased cost in the form of engineering support, material expense and manufacturing time. Moreover, desired sealing of the undercarriage of a vehicle may be impossible due to manufacturing constraints. Rearranging vehicle body parts to change airflow patterns has the same drawbacks. Even more problematic, predictions of aerodynamics and interior or exterior pressures for a specific vehicle are difficult or impossible to obtain during the initial design and engineering stage of a vehicle. The assembly and testing of a full scale prototype is required in order to obtain such characteristics accurately.
The present application provides a solution for reducing the amount of exhaust fumes entering the passenger compartment of a motor vehicle without the above drawbacks.